Bird wing shape is driven by environment and behavior

A new study has revealed that birds adapted certain types of wing shapes based on their environment and behavior. The research was focused on wing measurements from 10,000 bird species. 

Understanding how different organisms move around is very important for conserving biodiversity. Since tracking the movement of animals can be very expensive, there are still many things that are not known about their movement and dispersal. 

The activities of animals in remote locations are especially mysterious, but studying bird wings can provide important clues. 

The Arctic tern makes a long annual journey from the Arctic to the Antarctic and back again. On the other side of the spectrum, the Inaccessible Island rail is the world’s smallest flightless bird, which never leaves the five-square-mile radius of its island.

Measurements of wing shape, such as the elongation of the wing, indicate how well the wing is adapted for long-distance flight. 

A team led by the University of Bristol measured the wings of 45,801 birds in museums and field sites around the world. Using these measurements, the researchers created a map of the global variation in wing shape. The study revealed that the best-adapted fliers were primarily found in high latitudes, while birds with more sedentary lifestyles were mainly found in the tropics.

By comparing these values with detailed information about each species’ environment, ecology, and behavior, the experts found that the geographical differences in wing shape are primarily driven by temperature variability, territory defense, and migration.

“This geographic pattern is really striking,” said study lead author Dr. Catherine Sheard. “Given the role we know dispersal plays in evolutionary processes, from speciation to species interactions, we suspect this relationship between behavior, the environment, and dispersal may be shaping other aspects of biodiversity.”

The study is the first comprehensive analysis of a dispersal-linked trait across an entire class of animals.

The research is published in the journal Nature Communications.

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By Chrissy Sexton, Earth.com Staff Writer